A unicast frame is bridged to a single recipient device in a packet-switched computer network. A Media Access Control (MAC) address of the recipient device is typically stored within an address table that has been populated using a broadcast flooding operation. The address table is maintained at a bridging device that is coupled to the networks. Where the MAC address of the recipient device cannot be located in the address table, the unicast frame is forwarded to all of the bridged networks.
Maintaining the address table can burden the processing and storage resources of the bridging device. Additionally, not all networked device addresses may be stored in the address table. For instance, a MAC address is not stored for a port that has not generated traffic on the bridging device. In such a case, the bridging device applies pressure on all networks by transmitting the unicast frames to every network. Moreover, MAC addresses stored in the address table can become outdated. For example, a port may be moved to a new network, causing the bridging device to forward the unicast frame to the wrong recipient device.